Randomize pictures

[Trevor Newell]

Hm - DirectRT definitely offers a lot of different options to accomplish the task you need. The first items you may want to look into include the RBG (randomize between groups) and RWG (randomize within groups) features. For more information see the following links:
RWG - http://www.empirisoft.com/directrt/h...amples_rwg.htm
RBG - http://www.empirisoft.com/directrt/h...amples_rbg.htm
RBG & RWG - http://www.empirisoft.com/directrt/h...es_rbg_rwg.htm

You may also want to look into using stimlists. Through stimlists you can choose to present a variety of stimuli in a specified order (the order follows throughout the entire experiment), present the stimuli in a 'true randomization', or present the stimuli in a randomization sequence that only presents each stimuli once. For more information, see the following link:
http://www.empirisoft.com/directrt/h..._stimlists.htm

[snyderf]

Hi, Thank you for your reply. I've previously looked at the DirectRT tutorial and user's manual and am familiar with RWG, RBG, and stimlists, so I must be confused. I know how to randomly select a picture from a group of pictures (perhaps using a stimlist), but I'm not sure how to keep the same image for a set of questions. This way each subject would receive a randomly generated picture for their first question and continue to see the same picture for their remaining set of questions.

Also, as I mentioned in my second question, is there any work around to randomize pictures between subjects.

Sorry if I'm not getting this. Perhaps and example would help.

Thanks again.